Electrical appliances have become a vital part of virtually every household and business. Common electrical appliances include curling irons, flat irons, hair dryers, air compressors, electric tools, coffee pots, electric cookers, electric blankets, heating pads, computers and the like. Most common electrical appliances are used by homeowners each and every day and often are an important tool used in the home and/or business. Despite the enormous advantages common appliances afford users, there are also disadvantages. Such routine use of appliances often reduces the user's awareness of the operational state of the appliance. Also, users are often distracted or otherwise inattentive to the appliance.
A large percentage of household fires are attributable to inattentive use of electrical appliances. Frequently, such fires are caused by appliances that generate heat, i.e., hair dryers, curling irons, clothing irons, heating pads and the like. According to the U.S. Fire Administration, between 1998 and 2007, there were an estimated 397,650 residential structure fires annually resulting in 3,040 deaths and 14,960 injuries each year. These fires resulted in an average dollar loss of $6,029 million. In 2006, approximately 11.4 percent of those fires were attributable to heating, which includes such heat generating appliances. See www.usfa.dhs.gov, last visited on Feb. 5, 2009.
Another concern when using appliances is the energy usage, and thus cost associated with use. All electrical appliances consume energy. The cost of operating an electrical appliance ranges from several dollars to hundreds of dollars each year, depending on such things as the frequency of use and size of the appliance. Inattentive users frequently forget to turn off an appliance when they are finished using it and therefore the appliance continues to consume, and waste energy which also adds cost to their energy bill.
In recent years, the trend in appliance design has been to include an auto-shutoff feature for at least some appliances which removes power from the appliance after a predetermined time from when the appliance was turned on. However, these additional features add cost and complexity to the appliance design and manufacture. Therefore, many new appliances do not include an auto-shutoff feature. Also, there are a significant number of appliances already in use that were not manufactured with an auto-shutoff feature.
Thus, a need exists for a power supply switch that can be positioned between a power source and the appliance, the power supply switch operating to remove the power from the power source to the appliance after a delay time.